When i eat my stomach burns. i notice it happens more often when i eat potato chips, ketchup, onions, and tomatoes. sometimes when i drink water it bu?

Heartburn?: Sounds like you may have heartburn aka reflux aka GERD. Most people get flares when they eat something that triggers it, and then can have symptoms for days or more whenever they eat or lie down. Try avoiding acid inducing foods, alcohol and smoking, and eating late at night. If symptoms continue you should get evaluated. For more info: http://stanford.io/2ezd9w9